Clogs in pipes are a nuisance, especially underground. Releasing the clogs typically requires time, manpower, tools and/or machinery, and may cause annoyances such as blocking roads and delays until manpower is available.
Some methods and mechanisms for dealing with obstructions in piping systems for sewage drainage or rain water runoff and the like have been devised. DE 3300489 discloses an apparatus comprising a screen for retaining and removing substances that may clog an outlet opening; and DE 3822555 relates to a throttle device for an outflow opening of a rainwater-retention chamber in a drainage system.
U.S. Pat. No. 5,967,175 describes a waste-line stoppage detector and automatic water shutoff system that is utilized to prevent the overflow of raw sewage from a plumbing fixture. Electronic shutoff valves are electronically connected to a waste line stoppage detector. The electronic waste line stoppage detector may be electronic, use a diaphragm or float ball with a switch.
U.S. Pat. No. 4,083,661 discloses a pneumatic sewage ejector that includes a tank for holding fluid sewage. When the sewage reaches a predetermined high level in the tank, it is ejected by pressurized air forced into the tank through a valve located inside the tank. The ejection of the fluid is initiated by a float which responds to the high fluid level in the tank by ascending and thereby moving the valve to an air-input position to admit pressurized air into the tank to expel the sewage. The valve remains in the air-input position until the fluid reaches a low level, at which time the float descends and moves the valve to a vent position to vent the pressurized air to the atmosphere. The float moves the valve between the air-input position and the vent position in one discrete step so that the valve cannot stop in an intermediate position.
The above-mentioned references are incorporated herein by reference in their entirety.